[PATCH v2] cxgbi: cxgb4i: Added pointer check

[PATCH v2] cxgbi: cxgb4i: Added pointer check

[Denis Arefev]

Return value of a function 'alloc_wr' is dereferenced at cxgb4i.c:624
without checking for null, but it is usually checked for this function

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Arefev <arefev@swemel.ru>
---
 drivers/scsi/cxgbi/cxgb4i/cxgb4i.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
index 2c3491528d42..b93bd36dcb2d 100644
--- a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
+++ b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
@@ -620,6 +620,8 @@ static inline int send_tx_flowc_wr(struct cxgbi_sock *csk)
 #endif
 	flowclen16 = tx_flowc_wr_credits(&nparams, &flowclen);
 	skb = alloc_wr(flowclen, 0, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
 	flowc = (struct fw_flowc_wr *)skb->head;
 	flowc->op_to_nparams =
 		htonl(FW_WR_OP_V(FW_FLOWC_WR) | FW_FLOWC_WR_NPARAMS_V(nparams));
-- 
2.25.1

Re: [PATCH v2] cxgbi: cxgb4i: Added pointer check

[Mike Christie]

Replace Karen with Varun.

On 11/18/22 6:17 AM, Denis Arefev wrote:
> Return value of a function 'alloc_wr' is dereferenced at cxgb4i.c:624
> without checking for null, but it is usually checked for this function
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Denis Arefev <arefev@swemel.ru>
> ---
>  drivers/scsi/cxgbi/cxgb4i/cxgb4i.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
> index 2c3491528d42..b93bd36dcb2d 100644
> --- a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
> +++ b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
> @@ -620,6 +620,8 @@ static inline int send_tx_flowc_wr(struct cxgbi_sock *csk)
>  #endif
>  	flowclen16 = tx_flowc_wr_credits(&nparams, &flowclen);
>  	skb = alloc_wr(flowclen, 0, GFP_ATOMIC);
> +	if (!skb)
> +		return -ENOMEM;

If this returns a negative value push_tx_frames is going to mishandle it.
I'm not sure how to best handle the failure there, but I cc'd the correct
maintainer, Varun.

RE: [PATCH v2] cxgbi: cxgb4i: Added pointer check

[Varun Prakash]

>> Return value of a function 'alloc_wr' is dereferenced at cxgb4i.c:624
>> without checking for null, but it is usually checked for this function
>> 
>> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>> 
>> Signed-off-by: Denis Arefev <arefev@swemel.ru>
>> ---
>>  drivers/scsi/cxgbi/cxgb4i/cxgb4i.c | 2 ++
>>  1 file changed, 2 insertions(+)
>> 
>> diff --git a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
>> index 2c3491528d42..b93bd36dcb2d 100644
>> --- a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
>> +++ b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
>> @@ -620,6 +620,8 @@ static inline int send_tx_flowc_wr(struct cxgbi_sock *csk)
>>  #endif
>>  	flowclen16 = tx_flowc_wr_credits(&nparams, &flowclen);
>>  	skb = alloc_wr(flowclen, 0, GFP_ATOMIC);
>> +	if (!skb)
>> +		return -ENOMEM;
>
>If this returns a negative value push_tx_frames is going to mishandle it.
>I'm not sure how to best handle the failure there, but I cc'd the correct
>maintainer, Varun.

push_tx_frames() can not handle negative return value from send_tx_flowc_wr(),
to fix this issue we can preallocate a skb in alloc_cpls() and use this skb in send_tx_flowc_wr().